The magnetic suspension and rotation of steel ball rotors and steel needles has been known since the 1930's. The speeds of rotation and the generated "g" forces have been continuously increasing, wherein it is now possible to magnetically spin steel balls of 0.5 millimeter at speeds of 10.sup.6 revolutions per second, with centrifugal forces exceeding 10.sup.9 g.
It has been determined that an inverse relationship exists between the diameter of the steel ball and the centrifugal force at which the steel ball will burst.
To date, no attempts have been made to apply the above-mentioned technique to the investigation of substances and materials for practical purposes.
The highest spin forces achieved with standard centrifuges, i.e. rotors driven by a motor or turbine, rarely exceed 3.times.10.sup.5 g.
The idea of centrifugation of microscopical samples of biological material in non-magnetic rotors of several millimeters in diameter was expressed recently by this inventor (Moroz, 1980).sup.1. In a later article, a rotor has been suggested, which is a hollow glass microsphere filled with magnetic material and living cells through an opening therein (Moroz, 1984).sup.2.
However, the implementation of a rotor comprising an open hollow microsphere is not easily accomplished. Microspheres are not yet commercially available, and the samples that can be used with such small rotors are too small for practical purposes. Also, an opening in such a rotor poses encapsulation problems. Therefore, this invention features a closed rotor for practical biomedical, biochemical and laboratory applications.
Such closed rotors can be larger, approximately 1 cm in diameter or less and can be round or dish-shaped. The rotor can consist of two portions, one magnetic or magnetizable, and the other being of a transparent material, so the sample can be observed during rotation. The two respective portions can be comprised of steel and glass. This microvessel can be fabricated by engaging and sealing two separate corresponding sections about a sample, i.e. the sample can be encapsulated in the rotor.
Generally such a rotor will be usable only once, and must be stored or discarded after its initial use.
In some high "g" force applications, the microvessel may comprise prestressed materials that will counteract the higher centrifugal forces, or the microvessel may be coated with a shrinkable plastic that will prestress the rotor.
Such rotors, will be capable of rotating at forces generally exceeding 5.times.10.sup.5 g.
The transparent section of the rotor allows the sample to be illuminated and microscopically observed during rotation. Because the image will be blurred at high speed, stroboscopic illumination can be utilized (Moroz, 1980).sup.1.
The techniques of suspending and rotating a magnetic or magnetizable rotor in a rotating magnetic field are well known, and have been devised by Beams.sup.3 and Shimizu et al.sup.4.